Weekly terminal cleaning may help keep OR bacterial counts low

VERSION 2 — FULL ANALYSIS

A new JAVMA study is putting a sharper point on a routine question in veterinary surgery: how often should operating rooms get terminal cleaning? Based on two years of air sampling in six small animal operating rooms at a veterinary teaching hospital, the authors concluded that weekly terminal cleaning should be considered to maintain acceptable airborne bacterial counts for general surgery, while total joint replacement cases may justify terminal cleaning within 24 hours. (ecvs.org)

That recommendation stands out because veterinary-specific evidence on terminal cleaning frequency has been sparse. In the ECVS presentation summarizing the work, the authors said no specific published recommendations had previously addressed how often terminal cleaning should occur in veterinary operating rooms. In human healthcare, environmental cleaning guidance is more established, but even there, the exact frequency of deeper scheduled cleaning can vary by room use, patient risk, and local protocols. CDC guidance supports scheduled cleaning of operating room surfaces and equipment, and broader operating room literature describes weekly or every-other-week total clean-up in addition to start-of-day, between-case, and end-of-day cleaning. (ecvs.org)

The veterinary study used passive air monitoring with blood agar settle plates exposed for 60 minutes during surgery, then calculated the Index of Microbial Air contamination. According to the conference summary, researchers sampled six small animal ORs and examined how time since terminal cleaning affected airborne bacterial load, along with other contributors to contamination. Their bottom-line recommendation was practical: weekly terminal cleaning for general surgery rooms, and terminal cleaning within 24 hours before total joint replacement, where the acceptable contamination threshold is lower. (ecvs.org)

The broader literature helps explain why timing matters. Airborne contamination in operating rooms is influenced by occupancy, staff movement, ventilation, attire compliance, and environmental cleaning. A South African veterinary theatre study found frequent isolation of airborne organisms, including species previously implicated in canine and feline surgical site infections, and concluded that routine, frequent, thorough cleaning should be part of bioburden control. CDC guidance also notes that operating room air can contain microorganisms, dust, skin cells, and respiratory droplets, while human operating room studies have linked environmental surveillance and feedback to lower contamination and, in some settings, fewer surgical site infections. (scielo.org.za)

There doesn't appear to be much published outside commentary yet on this specific JAVMA paper, but related expert discussion in veterinary surgery circles has emphasized the study's practical value. The ECVS summary described settle plate sampling as simple and cost-effective for routine monitoring, which could make it attractive for referral hospitals and teaching institutions looking for a feasible surveillance tool rather than a one-time audit. That said, the evidence here is observational and focused on airborne counts, not direct patient outcomes, so it should be read as a risk-reduction signal rather than a stand-alone infection-prevention rule. (ecvs.org)

Why it matters: For veterinary professionals, the study offers a usable benchmark in a part of perioperative infection control that often depends on habit, staffing, and facility design more than published evidence. A weekly terminal cleaning cadence may be a manageable standard for general small animal surgery suites, but the findings also support a more conservative approach for higher-stakes orthopedic procedures involving implants. Practices may want to review not just terminal cleaning schedules, but also room traffic, HVAC performance, attire compliance, and whether “clean” and “dirty” case flow is increasing airborne burden across the week. (ecvs.org)

What to watch: The next step is whether follow-up studies connect weekly terminal cleaning schedules and IMA thresholds to actual surgical site infection rates, and whether specialty groups translate this kind of evidence into formal veterinary operating room cleaning guidance. For now, the study gives hospitals a defensible starting point for policy review, especially if they perform total joint replacement or other implant procedures where a lower microbial load is likely worth the added operational effort. (ecvs.org)